Research On High Quality Dynamic Quadrilateral Mesh Sequence Generation Algorithm

In recent years,with the continuous development of information technology,a large number of 3D scanning and reconstruction techniques are emerging,and people have had the ability to obtain real-time dynamic data of a large number of 3D models.Applying these techniques to computer games and animation,people can easily obtain animated sequences of real-time animation characters represented by a series of triangular mesh models.However,compared with triangular mesh,quadrilateral mesh has the advantages of relatively more suitable for animation editing,mapping,etc.in the post production process of animation,so it is widely used in digital games and animation process.Due to the global and local characteristics of quadrilateral meshes,the generation process of quadrangular meshes should not only meet the requirements of local geometric constraints but also meet the global demand,so the generation of the high quality quadrilateral meshes is not a simple thing.This dissertation focuses on the study of quad mesh sequence reconstruction methods based on the actual demand of digital animation and digital film production in the process of research,which used the dynamic triangle mesh sequence of 3D animation character as input.The main research works on how to avoid the distortion of 3D model in the process of animation,how to integrate the animation and symmetric attributes and how to model 3D animation with global optimization.We propose the automatic generation algorithm of animation aware quadrangulation with multi-resolution adaptivity,the quadrilateral mesh sequence generation algorithm of symmetric surfaces and the global optimization generation algorithm for the quadrilateral mesh sequence,and we also construct the geometry processing framework for 3D role models of quadrangular mesh sequence reconstruction.Main contributions of this dissertation are presented as follows:1.A multiresolution adaptive algorithm for the generation of animation aware quadrilateral mesh sequence is designed and implemented.Based on the analysis of the deformation characterization of density,sizing field of cross field is obtained to represent the stretching coefficient of deformation and also the quad mesh resolution.Our method is the automatic generation of quadrilateral mesh sequence with density to meet the needs of the deformation of animation ensuring the efficiency of the algorithm.Compared with the previous methods,our method can solve the distortion problem of 3D animation model in the process of deformation.The results of the expression accuracy and orthogonality of meshes show better in each frame of the animation,which is more suitable for 3D mesh reconstruction process in the animation with large deformation.2.The algorithm of quadrilateral mesh sequence generation for symmetric model is designed and implemented.We study the problem of generating the quad meshes of symmetric surfaces from triangle mesh sequences with high quality.We present a novel method to optimize the cross field in the first stage of quadrangulation pipeline to strike a balance between symmetry and animation.Our method is semi-automatic,which need a few input symmetry points by the user.The experimental results we obtained show better in the global symmetry feature and the local geometric deformation feature in each frame compared to the state-of-the-art algorithms,while the singularities are less..3.A novel algorithm for generating quadrilateral mesh sequence with global optimization.Different from the work that has been done for a single frame or the entire animation sequence as a whole,the key contribution is that our method first proposes a grouping strategy to decompose the input animation into subsequences,then calculates the cross fields of subsequences and merges them.The resulting cross field can better express the geometric and topological structure of the animation sequences,and then generate quadrilateral mesh sequence with high quality.